In an LSI process, particularly, in a microfabrication process after ArF lithography, edge roughness of a pattern (surface irregularity of a pattern end part) has a great influence on yield of a device as the pattern is refined. An occurrence degree of the roughness largely varies depending on a material constituting a semiconductor device, an exposure device, or properties and characteristics of a ground substrate, and the like. Particularly, in a mass production process, a size of the roughness has a great influence on performance of a product. Further, even though the roughness is not abnormally large, an appearance of characteristic roughness often reflects performance deterioration of a manufacturing device, such that there exists a possibility that the performance deterioration thereof may cause a product defect in the future. Accordingly, it is urgent to develop a system not only capable of observing a roughness shape of a pattern edge, but also capable of identifying an occurrence cause from characteristics thereof. Further, in consideration of the use in the mass production process, an inspection method is required to be non-destructive inspection.
As a background art in this technical field, PTL 1 discloses a measuring method of obtaining edge roughness of respective left and right sides of a line pattern as a 3σ value indicating a width of surface irregularity fluctuation based upon an ideal straight line. Further, in PTL 1, proposed herein is a method of analyzing an edge shape by performing Fourier analysis on a set of fluctuation data and obtaining intensity with respect to a spatial frequency.